1. Field of the Invention
The present invention relates to an endless rectilinear motion rolling guide unit that is suitably used in the sliding parts of various cutting machine tools, especially of heavy load cutting machine tools.
2. Description of the Prior Art
An endless rectilinear motion rolling guide unit was disclosed by Japanese Patent Application Disclosure No. 116119-1986 utilizing not only rolling friction but also sliding friction to a great extent so that without harming efficient rolling characteristics, it can greatly reduce vibration of machine. In the prior art rectilinear motion rolling unit, use was made, as rolling friction element, of a plurality of balls, while a friction member was used as sliding friction member that was pressed under spring force against the underlying track rail member on which the slide unit moves.
Due to such a spring pressure-type construction as mentioned above, the pressure applied onto the slide friction member and thus onto the track rail member could not be greatly enhanced, therefore when the generated mechanical vibration became greater, the slide friction member could not give rise to any marked reduction effect thereon.
Further, when use was made, as rolling friction member, of cylindrical rollers in a rectilinear motion rolling guide unit, the braking power generated by such a spring pressure-type sliding friction member was too small to effectively reduce the vibration.